Interior Parts. Replacement Sources.

[BrierS]

My '87 300TD has some interior parts that needing or could use replacement. For example, one of the two plastic pieces housing the upper brake light and wiper motor's output shaft. Another is the tailgate guide plates. Where are some of the better sources for such parts? From reading the forum threads it appears to be a preference order when getting any parts is necessary. I.E. salvage first, MB last unless the part warrants the reverse. All opinions are welcome. Thanks. Steve